Electric cut-out



WITNESSES:

M J. sANDlN I ELECTRIC CUT-OUT vFiled June 17, `1920 "lulu/111 wwwINVENTOR M60/'ifs Jerome Sand/'n j ATTORNEY Patented June 2, 1925.

UNITED STATES 1,539,870 PATENT OFFICE.

MAURITS JEROME SANDIN, 0F WILKINSBURG, IENNSYLVANIA, ASSIGOR T0 WEST-INGHOUSE ELECTRIC &; MANUFACTURING SYLYANIA.

COMPANY, A CORPORATION or PENN- ELECTRIC CUT-OUT.

Application led June 17, 1920. Serial No. 389,567.

To all whom t may concern:

Be it known that I, MAUR'rrs JEROME SANDIN, a citizen of the UnitedStates, and a resident of Wilkinsburg, in the county of Allegheny andState of Pennsylvania, have invented a new and useful Improvement inElectric Cut-Outs, of which the following is a specification.

My invention relates to electrical protective devices and particularlyto cut-Outs ha'Vingtime-limit characteristics for intel rupting circuitsin response to predetermined overloads.

One object of my invention is to provide a device ofV the .aboveindicated' Character that shall be simple and durable in Constructionand effective in operation.

'Another object of my invention is to provide an economical, renewable,thermalresponsive element for an electric cut-out that shallembody-fusible means for interrupting a circuit and heating means forthe fusible means, thereby eliminating the necessity Of having,` as apermanent member of the device, a heating coil that is subject todamage.

In electric circuits wheremotors'or other devices may be subjected 'toslight overloads for a Certain lengthlof timeit is desirable to providea protective device having a time-limit Characteristic. may beaccomplishedl by providing a thermal-responsive.circuit-interruptingmember that, on an overload of short duration, does not heatsufliciently to interrupt the circuit but which will interrupt thecircuit when. an overload continues for a considerable period of time.In cut-out of relatively small capacity, a heating coil of relativelysmall cross-sectional area and, therefore, likely to damage, isusuallyemployed.

In practicing my invention, I provide a Container or casing havingsuitable terminals and a resiliently biased member, connected to one ofthe terminals, disposed therein. A renewable thermal-re Onsive elementcomprises a relatively short eating Conductor of relativelyv highresistance provided, at one end, with a head or enlarged portion,.secured -in position by fusible means, that is separated from theconductor in response to a certain temperature.. The renewable elementis attached, at one end, to one of the casing terminals and is placedunder tension by the co-Operation of its headed end with the resilientlybiased member.

In response to a predetermined temperature in the heating Conductor, thehead of the element 1s moved quickly away from the heating conductor tointerrupt the circuit.

Figure 1 of the accompanying drawings is a plan view, partially insection and par tially elevation, of a cut-out embodying ing my1nvent1on.

Fig. 2 is a sectional side View ofthe de- A cut-out of the plug typeembodying my invention may comprlse, in general, an insulating containeror casing 1, a bottom terminal member 2, a side screw-sleeve terminal.member 3, a renewable termal-responsive element 4, a movable conductingmember 5, a spring 6, a transparent window or f disk 7 and a screw capmember 8. The casing 1, as shown in Figs. 1 and 2, is providedwith amain chamber 9 having a frusto-conical upper portion 10 and acylindrical lower portion 11. into which a sleeve' portion 12 projectsfrom the lower portion of the casing 1. An opening 13, of relativelysmall diameter, extends through the sleeve portion 12 to the lower endof the casing 1 where it is provided with an Outwardly-fiaring orcountersunk portion 14.

T he bottom terminal member 2, of substantially hollow-sleeve formationand iitted into an apertured disk or Washer 15, is provided, aty itsinner end, with an annular liange 16 disposed in the opening 14' for`holding it in position in the disk 15 and,

at its outer end, with a headed rtion 17 having a transverse slot 17. isheld against the bottom of the casing 1 by a flange. 1 8 on the terminalmember 3.

The spring 6, Connected at one end 19 tothe sleeve terminal member 3,'iswound e disk 15 helically about the sleeve portion 12 and is incompression between the bottom of the chamber 9 and the movableconducting member 5. The member constitutes substantially a washerhaving an opening 19l disposed over the opening 13 on the s eeve portion12.

The renewable thermalresponsive element`4 comprises a portion 20 ofrelatively thin conducting wire or otherconductor, preferably ofrelatively high resistance, to which a bead er ball 21 of solder orsuitable alloy is secured at one end. The wire 2() is embedded in thebead 21 and, therewith, constitutes a renewable element comprising thesource of heat by which it is actuated.

The mass or the bead 21 is such as to absorb a considerable amount ofthe heat from the wire 20, thereby furthering the timelimitcharacteristic caused by the construction of the element .and by thefact that the actuating heat is generated mainly in the wire.

The portion 2O of the element 4 is .placed through the openings 19a and13 and the washer 5 is depressed to compress the spring 6, after whichone end of the portion 20 is bent back into the slot 17 a of theterminal 2 and wrapped around the outer surface of the latter under thehead 17. The bead 21, being larger in diameter than the opening 19, willhold the washer 5 in depressed position.

Upon the occurrenceof an overload o f suiiieient duration to heat theelement 4 and the bead 21 to a predetermined degree, the

l bead 21 will be separated from the conductor 20 to interrupt thecircuit.

As shown in Fig. 7, any of the renewable elements 4 may be provided withan insulating coating 22 to prevent deterioration and to conserve .theheat in the element.'

In Figs. 3 and 4, the chamber 9 is of substantially cup-shape and,instead of the helical spring 6 and the washer 5, a composite member 23serves to hold the bead 2l and to separate it from the element 4. Theheating conductor 20 may be provided with a few helical turns 24 or beotherwise arranged to increase its heating capacity without altering the-length or function of the element. The member 23 may be provided with aslot 28 extending from the opening 19n to one edge thereof to receivethe element and thus permit the coil 24 to be larger, if

desired, than the opening 19a. Also, in this form, the bottom terminalmember 2 may be secured to a bottom wall 25 of the easing 1. In Fig. 5,a washer 26 takes the placefof the beads 21 in Figs. 1 to 4 and issecured to the end of the heating conductor 20 by a body of solder oralloy 27.

While Iv have shown and described particular forms of my invention,changes may be effected therein without departing from the spirit andscope thereof, as set forth in the appended claims.

I claim as my invention:

1. An electric cut-out device comprising a heating conductor, a body offusible material adhering' directly thereto, and conducting'means biasedagainst said body to complete a circuit and to interrupt' the circuit inresponse to a predetermined temperature.

2. A thermal-responsive device comprising a terminal member, arelatively short heating conductor-of relatively high resistancedetachably connected to the terminal, a body of fusible materialadhering thereto, and a separate conducting member movable with respectto the heating conductor .and normally yieldingly held against movementby said body and adapted to be released to interrupt a circuit inresponse to a predetermined temperature.

3. A thermal-responsive device comprising a terminal member, a heatingconductor, a body of fusible material adhering to one end thereof, and aconducting member movable with respect to the heating conductor andnormally yieldingly held against movement by engagement withsaid bodyand adapted to be released to interrupt a circuit in response to apredetermined temperature.

4. In an electric cut-out device, the combination with a casing, contactyterminals therefor, and a movable conducting member connected to one ofsaid terminals, of a separate thermal-responsive elementv comprising arelatively short length of heating conductor detaehably connected to theother of said terminal members, and fusible means adhering io theconductor for releasably engaging the movable member and for holding thesaid element in circuit relation to the terminals and for releasing thesame to open the circuit in response to a predetermined temperature.

5. In an electric cnt-ont device, the combination with a casing andcontact terminals therefor, of an apertured movable conducting memberconnected to one of said terminals, a thermal-responsive elementcomprising a heating conductor connected to the other of said terminalmembers, and a body of fusible material adhering to the heatingconductor and disposed in said aperture for holding the movable'memberin circuit relation to the terminals and for releasing the lflfl movablemember to open the circuit in respense to a predetermined temperature.

6. A thermal-responsive device comprisf ing a body of fusible material,a hea-ting conductor having a portion embedded therein, a movableconducting member' having an aperture by which it embraces the heatingconductor and resilient means for biasing the movable member againstsaid body.

7. In' an electric cut-out device of the plug-type, the combination withside' and bottom contact terminals therefor, of a resiliently biasedconducting member operatively connected to the side terminal, arenewable,thermal-responsive element comprising a heating conductorconnected to the bottom terminal, and a body of fusible materialadhering to the heating conductor normally disposed to hold theconducting member in circuit relation to the terminals and to releasethe conducting member toopen the circuit in response to predeterminedcircuit conditions.

8. In an electric lcut-out, the combination` with a casing and terminalmembers therefor, of a renewable thermal-responsive device comprising aheating conductor detachably secured at one end to a terminal'and havinan enlarged head of fusible material adhermgthereto by means of whichthe conductor 1s releasably attached to the other terminal.

9. In an electric cut-out, the-combinaton with a casing havin relativelymovable terminals therefor an a 4thermal-responsive link' for connectingthe terminals comprising a heating conductor detachably secured to oneterminal and having a fusible portion adhering thereto for engaging theother terminal and forl retaining it 1n operative relation with theconductor.

10. In an electric cut-out, a support, a pair of relativel movable'terminals, oney of which is. movab e with respectv to the support, and arenewable thermal-responsive ink for connecting the terminals comprisinga heating conductor detachably securedjat `fusib1e portion for engaginterminal and holding it in one end tothe one conductor and having astraight portion provided with an adherent the flexible and which ismoved longitudinally of the conductor and separated therefrom when thetem erature of the conductor has reached a pre etermined degree.

11. In an electric cut-out, a casing having a relatively smallperforation therethrough and having a chamber communicating therewith, aterminal secured to the casing and havin an opening therein registeredwith the said perforation, a second terminal with* in the chambermovable toward and away from the first terminal and provided with anopening, and a thermal-responsive device comprising a heating conductoradapted to Abe inserted through the openings in the terminals and-attached at one end to the first terminal and rovided at the other endwith an adherent usible head for engaging the movable terminal and forretaining it in operative relation with the said conductor.

'12. In an electric cut-out, a/ asing having a chamber 'therein and|'aire atively long and narrow perforation. extending therethrough, ailexible terminal in the chamber,

exed position a terminal adjacent one end of the perforation and aheating conductor in the perforation in the casing having a fusible headfor releasably attaching the conductor to the movable terminal. I ntestimony whereof, I have vhereunto subscribed m'y name 1. MAURITSJEROME SANDIN.

this 14th day of June

